Portable electronic devices are commonly used for communication and entertainment purposes. Portable electronic devices include devices such as smartphones, cellular phones, mobile communication devices, computers, portable computing devices, mobile computing devices, tablet computers, cameras, video players, smart watches, audio players, electronic media readers, two-way radios, global positioning satellite (GPS) devices, and/or other types of electronic computing or communication devices, including combinations thereof. Cases, covers, protective covers, enclosures, or encasements are sometimes used with these types of electronic devices in order to protect the devices from damage due to exposure to shock, impact, dropping, puncture, dust, dirt, water, snow, rain, mud, chemicals, and/or other potentially damaging forces or elements. Cases and covers are also sometimes used to supplement the functionality of the device or to change the aesthetics of the device.
Electronic devices are commonly powered by one or more internal batteries or other power sources. Batteries enable electronic devices to be used in a portable manner and/or without being tethered to a power source. These batteries are often rechargeable. Electronic devices with more features, such as larger displays and more computing power, typically consume the available power even more quickly. When an electronic device's battery is exhausted, the device may become unusable until the battery can be recharged or until the device can be connected to another battery or a power source, such as a wall outlet. Battery capacity for electronic devices may become an issue due to factors such as power requirements of the electronic device, extended usage of the electronic device, physical space constraints of the internal battery, power requirements of peripherals attached to the electronic device, temperature extremes, unavailability of a power source for charging, decreased battery capacity due to aging of the battery, decreased battery life due to the number of charge/discharge cycles the battery has endured, and the like, as well as combinations thereof. These factors can reduce the usefulness of the electronic device because usage of the device between recharges may be limited and the user may have to discontinue use of the device due to a depleted battery until an external power source is located.
In some situations, a user may carry a spare battery for the electronic device. The spare battery can be used as a replacement for a discharged battery. While carrying the spare battery enables the user to use the device again without having to find a charging source, swapping batteries has drawbacks. First, the user must remember to carry the spare battery(s), in addition to the electronic device. Second, the user must remember to keep the spare battery in a charged state in case it is needed. Third, replacing an exhausted battery, or swapping an exhausted battery out of the electronic device for charging purposes, typically requires that the device be shut down, restarted, and/or rebooted. This process is often inconvenient and typically results in temporary loss of use, communication, and/or data. Finally, when a charging source is available, the various batteries must be swapped into and out of the electronic device in order to charge them, unless a separate host-charging device is available for the extra battery.
In addition, rechargeable batteries often have characteristics that can be affected by characteristics of the charging processes. The capacity or operational characteristics of some rechargeable batteries may change based on how the battery is charged, discharged, and/or used. For example, battery capacity or characteristics may change depending on how the battery is charged or how many times the battery has been recharged. In addition, batteries may have different charging characteristics or efficiencies depending on the present charge level of the battery. As presented herein, battery usage and charging efficiency may be improved by varying the charging pattern or algorithm for the battery.
For at least the reasons discussed above, improved power solutions for portable electronic devices are desirable. Improved power solutions may include improvements such as cases or covers with one or more supplemental power sources that are capable of providing supplemental power to an electronic device. In some situations, the case may also protect the electronic device. The supplemental power sources may have increased capacities, reduced charging times, improved methods of capturing energy from other sources, and/or methods of providing power to the electronic device in more effective or efficient manners. While a power case is beneficial to the user of the electronic device, it is often preferable that the case not add too much size or bulk to the electronic device such that it can still be easily be stored, held, and carried. Cases for electronic devices are disclosed herein that address these and other problems. Some of the techniques disclosed herein may also be implemented in apparatuses or devices other than cases, such as in a wall charger or other apparatus used to charge or supply power to an electronic device.